So the first and biggest question is going to be about my bottom bracket and crank options. This is one spot that I am very fuzzy about in general with bikes, as I know that the standards can be rather varied.

Do I need to find a square tapered bottom bracket the like the old one I have in the bike currently or can I go with a "higher end" solution that can get me the group discount.

Seeing that the gruppo includes a bottom bracket you should be able to just install it without any problem. You'd have to make sure that you'd get the english threaded BB cups and not the Italian standard, of course. Do you already have a campy compatible wheelset or plan on getting a Campy compatable hub installed on your rear wheel? You can't use Shimano/Shram compatable freehub bodies with Campy cassettes.

I have a 105 hub on there at the moment, but my fortunate position of being able to gobble up these parts at wholesale, and I am in desperate need of new rims so I was planning on grabbing a campy hub as well as I was aware of the compatibility issues there.

Unfortunately I have to go all in with the drive train as I am still running 7 speed RSX/105 gear from a bygone era. So I figure, while I have access to everything on the cheap, I might as well do everything provided my budget can handle it.

Quite easy to tell - if the threads are not both right-handed (you have to turn the drive side clockwise to remove it) then it is an English BB. If both sides are right-handed threads (very unlikely, I can't think of a cannondale with Italian threads). If there are no threads and two small grooves about 10 mm inboard of the outer BB faces then it is BB30 (uncommon on those CAAD5 models, but possible if you have a team frame). There also is a small possibility that the frame could be BB30 with a threaded adapter pressed in, this would be pretty evident.